The present invention relates to a swash plate type compressor used in an air conditioner for a vehicle. Particularly, the present invention relates to a swash plate type compressor using a rotary valve for supplying a refrigerant gas into a gas compression chamber.
For example, in a swash plate type compressor disclosed in Japanese Patent Laid-Open No. 7-189902, single headed pistons are housed in a plurality of cylinder bores arranged around a rotary shaft extending through the center of a housing. Each piston linearly reciprocates in the corresponding cylinder bore. Further, in the housing, a swash plate is tiltably supported by the rotary shaft. The swash plate converts a rotational movement of the rotary shaft into a reciprocating motion of the pistons. The compressor includes a rotary valve for selectively supplying a refrigerant gas into compression chambers, each of which is defined in the one of the cylinder bores by the associated piston. The rotary valve is housed in a central bore which is provided in the housing, and is rotated integrally with the rotary shaft. A suction port for allowing the compression chamber to communicate with the central bore is formed inside the housing. A refrigerant supply passage, which is selectively allowed to communicate with the suction port, is formed in the rotary valve. During the suction stroke of each single headed piston, namely, when the piston is moved toward the bottom dead center from the top dead center, the refrigerant supply passage of the rotary valve communicates with the suction port to allow the refrigerant gas to flow into the compression chamber.
However, in the compressor disclosed in Japanese Patent Laid-Open No. 7-189902, the refrigerant gas which is compressed in the cylinder bores (compression chambers) leaks out of a clearance between the outer circumference surface of the rotary valve and the inner circumference surface of the central bore, and thus the compression efficiency is reduced.
An objective of the present invention is to provide a swash plate type compressor having excellent compression efficiency, thereby improving the sealing performance between the rotary valve and the housing.
In order to attain the above objective, the present invention provides a swash plate type compressor having a crank chamber defined in a housing, a swash plate mounted on a shaft extending in the crank chamber for the integral rotation, and a compression chamber defined in a cylinder bore by a piston coupled to the swash plate. The rotation of the swash plate allows the piston to reciprocatingly move linearly inside the cylinder bore to compress a refrigerant gas introduced into the compression chamber from a first area dominated by suction pressure and discharge the compressed refrigerant gas into a second area dominated by discharge pressure. The refrigerant gas contains oil that lubricates an interior of the compressor as the refrigerant gas flows therethrough. The compressor comprises a bleeding channel formed within the shaft; a rotary valve integrally rotatable with the shaft and disposed in an accommodating bore existing on an extension line of the shaft, wherein the rotary valve has an outer circumference surface and a suction passage rotated integrally with the shaft and allowing the cylinder bore and the first area to communicate with each other according to the rotation, wherein the suction passage communicates with the accommodating bore; an oil separator having a front end and a rear end and disposed on the bleeding channel, wherein the oil separator forms part of the bleeding channel and has a shape adapted to centrifuge the oil contained in the refrigerant gas passing therethrough by the rotation of the shaft; and a feeding passage for feeding the centrifuged oil to an interface between the outer circumference surface of the rotary valve and an inner circumference surface of the accommodating bore.
In the swash plate type compressor of the present invention, the accommodating bore has an inner wall that is close to the outer circumference surface of the rotary valve, and the bleeding channel through the oil separator is flared toward downstream from upstream of a refrigerant gas flow flowing therethrough, whereby the oil contained in the refrigerant gas passing through the oil separator is centrifuged from the refrigerant gas according to the rotation of the shaft. The compressor further comprises a feeding passage for feeding the centrifuged oil to an interface between the outer circumference surface of the rotary valve and the inner wall of the accommodating bore.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.